1. Field
The present disclosure relates generally to inspection systems, and in particular, to backscatter inspection systems. More particularly, the present disclosure relates to detecting a gap. Still more particularly, the present disclosure relates to a method and apparatus for detecting a gap between a fastener and an opening.
2. Background
A fastener may be inserted through an opening in a first object and a second object to connect the two objects in a workpiece. The mechanical interaction between the fastener and the opening may be called the fit. The fit may be affected by the size of the opening and the size of the fastener. Types of fits may include clearance fit, interference fit, or other desirable types of fit.
There may be variation in forming the openings in the first object and the second object. An allowable or expected amount of variation in a process may be called the tolerance of the process. There may be a tolerance for forming the opening. There may also be a tolerance for forming the fastener. As a result, there may be a tolerance for the gap between the fastener and the opening.
Further, a variety of sizes of fasteners may be present in a manufacturing environment. In some cases, a fastener having an undesirable size may be inadvertently selected and inserted into an opening. At least one of the tolerance of the opening, the size of the fastener, or the tolerance of the fastener may cause the fit between the fastener and the opening to be undesirable. In some cases, at least one of the tolerance of the opening, the size of the fastener, or the tolerance of the fastener may cause a gap between the fastener and the opening. In some cases, this gap may be out of tolerance.
After assembly of the workpiece, layers of material may be present over the fastener. Disassembly of the workpiece including removal of any layers over the fastener may be necessary to determine if a gap is present between the fastener and the opening. Further, disassembly of the workpiece including removal of any layers over the fastener may be necessary to determine if a gap between the fastener and the opening is out of tolerance.
Disassembly of the workpiece may take an undesirable amount of time. Further, disassembly of the workpiece may result in undesirable effects to the quality of the workpiece. Yet further, disassembly of the workpiece may have undesirable manufacturing costs.
Therefore, it would be desirable to have a method and apparatus that take into account at least some of the issues discussed above, as well as other possible issues. One issue may be to provide a method of detecting gaps without disassembly of the workpiece. Another issue may be to determine a size of a gap between a fastener and an opening without disassembly of the workpiece. Yet another issue may be to determine if a gap between a fastener and an opening is out of tolerance.